1. Field of the Invention
The present invention relates to power systems and more particularly to a closed cycle power system in which combustion is achieved at stoichiometric conditions.
2. Description of the Related Art
Conventional mechanical power systems such as electrical motors powered by high energy density batteries or fuel cells or dynamic isotope power systems (DIPS) have been identified for research conducted in determining Lunar and Mars surface system applications. However, these power systems are inherently limited in terms of mechanical work output capability attainable with a practical system size and weight. To perform heavy duty mechanical tasks, i.e., lunar excavation, tunneling and regolith removal for the base/habitat construction and in-situ material processing, more advanced, intelligent and autonomously controlled machines with higher torque, horsepower and mechanical advantages must be developed.
In the course of investigating possible power systems, the present Applicant has discovered the present closed cycle power system which is the subject of the present patent application. Although developed for extraterrestrial applications, in which closed loop systems are imperative, the present invention is also particularly adaptable for applications on earth due to its environmental advantages. In this closed loop system, environmental pollutants are not released into the environment.
U.S. Pat. No. 4,112,875, entitled "Hydrogen Fuel Engine", issued to Laumann et al., discloses a hydrogen-oxygen fueled internal combustion engine which utilizes an inert gas, such as argon, as a working fluid, to increase the efficiency of the engine, eliminate pollution, and facilitate operation of a closed cycle diesel engine system. Laumann et al. do not burn in stoichiometric conditions, thus requiring the addition of the inert gas diluent. Use of a diesel engine, such as proposed by Laumann et al., is problematic because the working fluid can become contaminated by the use of different fluid and engine lubricants which can escape into the steam/inert gas efflux because of blow-by effects.
U.S. Pat. No. 4,799,357, issued to Hanrahan et al., entitled "Closed Loop Regeneration System For Generating Mechanical Energy and the Method Therefor", discloses a closed loop power regeneration system which combines chlorine and hydrogen to form hydrogen chloride at high temperatures and pressures. The high temperature, high pressure hydrogen chloride is used to drive a turbine after which the heat from the hydrogen chloride is extracted for use in a regeneration system. The hydrogen chloride is converted to hydrogen and chlorine in the regeneration system.
The Hanrahan et al. system requires elaborate chemical processes to recover the molecular hydrogen and chlorine. It requires use of an expensive reactant, silver, to extract the chlorine atom. Furthermore, hydrochloric acid and chlorine are likely to be highly corrosive agents, limiting the operating lifetime of such a system.